Zein nanospheres assisting inorganic and organic drug combination to overcome stent implantation-induced thrombosis and infection.

The complication of stent implantation is the biggest obstacle to the success of its clinical application. In this study, we developed a combination way of 3D printing and the coating technique for preparation of functional polyurethane stents against stent implantation-induced thrombosis and postoperative infection. SEM, XPS, static water contact angle, and XRD demonstrated that the functional polyurethane stent had a 37 µm-thickness membrane composed of zein nanospheres (250-350 nm). Meanwhile, ZnO nanoparticles were encapsulated in zein nanospheres while heparin was adsorbed on the surface, causing 97.1 ± 6.4 % release of heparin in 120 min (first-order kinetic model) and 62.7 ± 5.6 % release of Zn2+ in 9 days (Korsmeyer-Peppas model). The mechanical analysis revealed that the functional polyurethane stents had about 8.61 MPa and 2.5 MPa tensile strength and bending strength, respectively. The in vitro biological analysis showed that the functional polyurethane stents had good EA.hy926 cells compatibility (97.9 ± 3.8 %), anti-coagulation response (comparable plasma protein, platelet adhesion and suppressed clotting) and sustained antibacterial activities by comparison with the bare polyurethane stent. The preliminary evaluation by rabbit ex vivo carotid artery intervention experiment demonstrated that the functional polyurethane stents could maintain blood circulation under the continuous stresses of blood flow. Meanwhile, the detailed data from the simulated implant infection experiment in vivo showed the functional polyurethane stents could effectively reduce microbial infection by 3-6 times lower and improve fibrosis and macrophage infiltration.

Heparinized polyvinyl alcohol to specifically adsorb low-density lipoprotein from plasma.

INTRODUCTION: A medical adsorbent for blood purification was developed to specifically adsorb low-density lipoprotein (LDL) from hypercholesterolemia patient's plasma by covalently immobilizing heparin onto the surface of polyvinyl alcohol (PVA) with the couplant toluence-2,4-diisocyanate (TDI). METHODS: We used IR to demonstrate the success of covalently immobilizing heparin onto the surface, and investigated its adsorption of LDL, and primarily evaluated its hemo-compatibility using tests for platelet adhesion, the degree of platelet activation and a hemolysis test. RESULTS: (1) Heparin was successfully covalently immobilized onto the surface, the maximum amount of heparin immobilized on the surface of 1g PVA-1799 granules was about 5 µg; (2) one optimal condition for adsorption of LDL from hyperlipidemia plasma was a pH within the range of 7.2∼9.5, accordingly the adsorptive ratio (adsorbent/g: plasma/L=1:2) for LDL was about 70%; (3) it exhibited good hemo-compatibility. CONCLUSION: The adsorbent results in satisfactory adsorption of LDL with good hemo-compatibility; it could potentially be used as a blood purification material, and immobilization of heparin onto medical materials may be a way to develop an LDL-specific adsorbent for blood purification.

[Transformation of Dunaliella salina by using glass beads--a novel transformation method].

A novel transformation method was firstly established using glass beads in Dunaliella salina (D. salina). The results showed that the GUS gene, a reporter gene, was successfully expressed in D. salina. Cells of D. salina presented blue color under the microscope after stained. In addition, different factors which influenced transformation were optimized including the transformation consecutive time, rotate speed, concentration of the plasmid and PEG 6000. The experiment indicated that this fit together can obtain the best results for D. salina transformation: adding 150 microL PEG and 90 microL plasmid DNA to 800 microL culture of D. salina (10(6) cells/mL) containing 300 mg glass beads, swirling 12 seconds under the rotate speed 2400r/min. This newly method can be used as a potential tool in the research of D. salina gene engineering with the advantage of more simpleness, convenience, quickness and less expense.